[thin film transistor array and repairing method thereof]

ABSTRACT

A repairing method of thin film transistor array is provided. The repairing method of thin film transistor array can remove a residue between pixel electrodes so as to prevent the residue from electrically connecting pixel electrodes adjacent to each other. The repairing method of thin film transistor array can also be provided to remove a portion of the pixel electrodes above a particle or a defect, which may cause leakage of a storage capacity. The parameters of repairing method of the thin film transistor array precisely controlled and the yield of the thin film transistor array can be effectively improved.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Taiwan applicationserial no. 93111378, filed Apr. 23, 2004.

BACKGROUND OF INVENTION

1. Field of the Invention

The present invention relates to a thin film transistor array (TFTarray) and repairing method thereof. More particularly, the presentinvention relates to a thin film transistor array (TFT array) andrepairing method thereof, which can significantly improve yields of arepair process.

2. Description of Related Art

The proliferation of multi-media systems in our society depends ondevelopment of semiconductor devices and display devices. Displaydevices such as the cathode ray tube (CRT) have been used for quite sometime due to its remarkable display quality, reliability and low costs.Although the conventional CRT has many advantages, the design of theelectron gun renders it heavy, bulky and energy wasting. Moreover, thereis always some potential danger of hurting viewer's eyes due to itsemission of some radiation. With big leaps in the techniques ofmanufacturing semiconductor devices and opto-electronics devices, highpicture quality, slim, low power consumption and radiation-free displayssuch as the thin film transistor liquid crystal displays (TFT-LCD) havegradually become mainstream display products.

Generally, a color TFT-LCD includes a color filter (C/F), a TFT arrayand a liquid crystal layer disposed therebetween. The TFT array includesa plurality of thin film transistors, which are arranged in an areaarray and are connected with a plurality of scan lines and data lines.Each thin film transistor is disposed in a pixel area and iselectrically connected to a corresponding pixel electrode formed byindium tin oxide (ITO), indium zinc oxide (IZO) or other transparentconductive materials. Each thin film transistor is used to drive theliquid crystal layer to show various gray levels. Furthermore, in apixel of the conventional TFT array, a storage capacitor (Cst) may beformed between a pixel electrode, the corresponding scan line and adielectric layer. (e.g. a gate insulating layer and/or a passivationlayer) Also, the storage capacitor (Cst) can be formed between a pixelelectrode, a common line and a dielectric layer to provide betterpicture quality.

However, during a patterning process of the pixel electrodes of theconventional TFT array, two adjacent pixel electrodes may abnormallyconnect to each other because of an ITO or IZO residue therebetween.Furthermore, particles or defects within the dielectric layer of thestorage capacitor resulting from contamination may cause the leakagebetween an upper electrode and a bottom electrode of the storagecapacitor. The particles or defects make pixels display abnormally andthe picture quality of the display is degraded. In order to resolve theproblems mentioned above, a laser welding process between the upperelectrode and the bottom electrode of a defective storage capacitor isperformed to darken a defective pixel. It is noted that the number ofthe dark defects is increased because the laser welding processmentioned above is performed.

SUMMARY OF INVENTION

The present invention is directed to a thin film transistor array,wherein leakage between an upper electrode and a bottom electrode of astorage capacitor resulting from particles or defects can be reduced sothat yield of the manufacturing processes can be improved.

The present invention is directed to a repairing method of a thin filmtransistor array comprising a step of removing a residue, which maycause an abnormal electrical connection between pixel electrodes.

The present invention is directed to a repairing method of a thin filmtransistor array comprising a step of removing a portion of a pixelelectrode above particles or defects for reducing leakage between anupper electrode and a bottom electrode of a storage capacitor resultingfrom the particles or defects.

The present invention is directed to a repairing method of a thin filmtransistor array comprising a step of applying pulse beams to reduce thedamage probability of the neighboring devices, wherein the energy of thepulse beams can be controlled and fine tuned precisely to improve yieldof the manufacturing processes.

The present invention is directed to a film removing method comprising astep of applying pulse beams, wherein the energy of the pulse beams canbe controlled and fine tuned precisely to improve yield of themanufacturing processes.

According to an embodiment of the present invention, the thin filmtransistor array comprising a substrate, a plurality of scan lines, aplurality of data lines, a plurality of thin film transistors and aplurality of pixel electrodes is provided. The scan lines and the datalines are disposed over the substrate and the substrate is defined intoa plurality of pixel areas by the scan lines and the data lines. Eachthin film transistor is disposed in one of the pixel areas and isconnected with the scan lines and the data lines correspondingly. Eachpixel electrode is disposed in one of the pixel areas and iselectrically connected to one of the thin film transistorscorrespondingly. A portion of each pixel electrode is located above oneof the scan lines to form a storage capacitor, and one of the scan linesand a defect pixel electrode of the pixel electrodes have a particle ora defect therebetween wherein the defect pixel electrode furthercomprises an opening corresponding to the particle or the defect.Therefore, the leakage of the defective storage capacitor can bereduced.

According to an embodiment of the present invention, the thin filmtransistor array including a substrate, a plurality of scan lines, aplurality of data lines, a plurality of thin film transistors, aplurality of pixel electrodes and a plurality of common lines isprovided. The scan lines and the data lines are disposed over thesubstrate and the substrate is defined into a plurality of pixel areasby the scan lines and the data lines. Each thin film transistor isdisposed in one of the pixel areas and is connected with the scan linesand the data lines correspondingly. Each pixel electrode is disposed inone of the pixel areas and is electrically connected to one of the thinfilm transistors correspondingly. The common lines are disposed over thesubstrate and a portion of each common line is located above one of thecommon lines to form a storage capacitor, and one of the common linesand a defect pixel electrode of the pixel electrode have a particle or adefect therebetween, wherein the defect pixel electrode furthercomprises an opening corresponding to the particle or the defect.Therefore, the leakage of the defect storage capacitor can be reduced.

In an embodiment of the present invention, the thin film transistorarray further comprises a dielectric layer disposed between the pixelelectrodes and the scan lines or between the pixel electrodes and thescan lines.

According to an embodiment of the present invention, the method forrepairing a thin film transistor array having a plurality of pixelelectrodes is provided, wherein the pixel electrodes are electricallyconnected to each other through a residue therebetween. The repairingmethod, according to the present embodiment of the present invention,comprises a step of applying at least one pulse beam having a pulseduration between 1/20 of a second and ¼ of a second onto the residue toremove at least a portion of the residue such that the pixel electrodesadjacent to the residue are electrically isolated.

According to an embodiment of the present invention, the inventionprovides a method of repairing a thin film transistor array having aplurality of storage capacitors over scan lines (Cst on gate) or overcommon lines (Cst on common), wherein a pixel electrode and one of thescan lines or one of the common lines corresponding to the pixelelectrode have a particle or a defect therebetween. The repairing methodcomprises a step of applying at least one pulse beam having a pulseduration between 1/20 of a second and ¼ of a second onto the pixelelectrode to remove at least a portion of the pixel electrode above theparticle or the defect.

In the repairing method, according to an embodiment of the presentinvention, the pulse duration is, for example, between 1/11 of a secondand ¼ of a second, and the preferred pulse duration is 0.1 second.Furthermore, the pulse beam may be a pulse laser beam with wavelengthbetween 300 nm and 500 nm.

According to an embodiment of the present invention, the film removingmethod suitable for removing a film formed over a thin film transistorarray is provided. The film removing method comprises a step of applyingat least one pulse beam having a pulse duration between 1/20 of a secondand ¼ of a second onto the film to remove at least a portion of thefilm.

In the film removing method of the present invention, the pulse durationis, for example, between 1/11 of a second and ¼ of a second, and thepreferred pulse duration is 0.1 second. Furthermore, the pulse beam maybe a pulse laser beam with wavelength between 300 nm and 500 nm.

In the repairing method, according to an embodiment of the presentinvention, the residue between pixel electrodes is removed for reducingabnormal electrical connection between two adjacent pixel electrodes.Moreover, the repairing method of the TFT array may also comprises astep of removing a portion of the pixel electrode above the particles ordefects to ensure that the storage capacitor can operate consistently.Since the repairing method is performed with the pulse beams, which canbe controlled and fine-tuned, the residue above devices can be preciselyremoved so as to improve yield of the manufacturing processes.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, and are intended toprovide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 and FIG. 2 are top views of a thin film transistor arrayaccording to an embodiment of the present invention.

FIG. 3A is a top view of a thin film transistor array according toanother embodiment of the present invention.

FIG. 3B is a cross-sectional view along line A-A′ of FIG. 3A.

FIG. 4A and FIG. 4B are views of thin film transistor arrays shown FIG.3A and FIG. 3B after repairing.

FIG. 5A is a top view of a thin film transistor array according to stillanother embodiment of the present invention.

FIG. 5B is a cross-sectional view along line B-B′ of FIG. 5A.

FIG. 6A and FIG. 6B are views of thin film transistor arrays shown FIG.5A and FIG. 5B after repairing.

DETAILED DESCRIPTION

FIG. 1 is a top view of a thin film transistor array according to anembodiment of the present invention. Referring to FIG. 1, a thin filmtransistor array 100, according to an embodiment of the presentinvention, comprises a substrate 110 (shown in FIG. 3B), a plurality ofscan lines 120, a plurality of data lines 130, a plurality of thin filmtransistors 140 and a plurality of pixel electrodes 150. The scan lines120 and the data lines 130 are disposed over the substrate 100 and thesubstrate 100 is defined into a plurality of pixel areas 110 a by thescan lines 120 and the data lines 130. Each thin film transistor 140 isdisposed in one of the pixel areas 110 a and is connected with the scanlines 120 and the data lines 130 correspondingly. Furthermore, eachpixel electrode 150 is disposed in one of the pixel areas 110 a and iselectrically connected to one of the thin film transistors 140correspondingly. In an embodiment of the present invention, the materialof the pixel electrode 150 includes transparent conductive material,such as indium tin oxide (ITO) or indium zinc oxide. In order tosimplify the drawings, only few elements are described with reference toFIG. 1. In fact, the thin film transistor array 100 further comprisesstorage capacitors having a Cst over scan lines (Cst on gate) or a Cstover common lines (Cst on common).

Referring FIG. 1, during the patterning process of the pixel electrodes150, a residue 160, such as an ITO residue or an IZO residue, may remainbetween above the data lines 130. In this regard, the pixel electrodes150 adjacent to the data line 130 may be electrically connected to eachother through the residue 160. Therefore, the thin film transistor array100 cannot operate regularly. For this reason, the present inventionprovides a repairing method of the thin film transistor array 100 toresolve the problem resulted from the residue 160.

As shown in FIG. 1, the repairing method of the thin film transistorarray 100 comprises a step of applying at least one pulse beam having apulse duration between 1/20 of a second and ¼ of a second onto an jointarea 170 between the residue 160 and the pixel electrodes 150.Therefore, the pixel electrodes 150 adjacent to the residue 160 areelectrically isolated from each other. However, in another embodimentsof the present invention, the residue 160 may be entirely or partiallyremoved. Furthermore, except for the joint area 170, other portions ofthe residue 160 or may be removed to electrically isolate the pixelelectrodes 150. Moreover, the pulse duration of the pulse beam is, forexample, between 1/20 of a second and ¼ of a second. In an embodiment ofthe present invention, the pulse duration is, for example, between 1/11of a second and ¼ of a second, and the preferred pulse duration is about0.1 second. Furthermore, the pulse beam is, for example, a pulse laserbeam with wavelength between 300 nm and 500 nm.

It should be noted that the pulse duration mentioned above is an actionperiod of each pulse beam. In other words, if the pulse duration of thepulse beam is T, an F value of the pulse beam is equal to 1/T. Duringthe actual operation, the pulse duration and the frequency (i.e. shotsper second, but not the F value) of the pulse beam determine a totalaction period. For example, when the pulse duration of the pulse beam is0.1 second (i.e. the F value of the pulse beam is 10) and the frequencyof the pulse beam is 2 (i.e. two shots per second), the total actionperiod is 0.2 second.

In the repairing method, according to an embodiment of the presentinvention, the residue is removed by applying a pulse beam. Since thetotal action the pulse duration and the frequency of the pulse beamdetermine periods, precise controlling and fine-tuning of the energy ofthe pulse beams make possible. Therefore, the repairing operation can beperformed precisely. However, the position of the residue is illustratedfor describing the embodiments of the present invention, the residue maybe located at any position of the thin film transistor array. Forexample, the residue may be located above the scan lines or the thinfilm transistors. By using the repairing method of the presentinvention, damage of circuits or devices underneath the residue causedby pulse beams having excess energy can be substantially reduced.

Referring to FIG. 2, the residue 160 is located above the thin filmtransistor 140, similarly, the residue 160 located above the thin filmtransistor 140 can be entirely or partially removed by the repairingmethod of the present invention. Therefore, the pixel electrodes 150adjacent to the residue 160 are electrically isolated from each other.However, the repairing procedures are similar to the embodiment shown inFIG. 1, and therefore the detail description is omitted.

FIG. 3A is a top view of a thin film transistor array according toanother embodiment of the present invention; and FIG. 3B is across-sectional view along line A-A′ of FIG. 3A. Referring to FIG. 3Aand FIG. 3B, the same reference number shown in FIG. 1, FIG. 3A and FIG.3B represents the same element, and the detail description of which isomitted. In an embodiment of the present invention, the pixel electrode150 extends to an area above the scan line 120. A dielectric layer 181,which comprises a gate-insulating layer 182 and a passivation layer 184extending from the thin film transistor 140, is disposed between thepixel electrode 150 and the scan line 120. The pixel electrode 150 andthe scan line 120 form a storage capacitor. Furthermore, the particlesor the defects 186 resulting from contamination remains in thedielectric layer 181, and the particles or the defects 186 locatedbetween the pixel electrode 150 and the scan line 120 may result in theleakage of the storage capacitor.

FIG. 4A and FIG. 4B are thin film transistor arrays shown FIG. 3A andFIG. 3B after repairing. Referring to FIG. 4A and FIG. 4B, in order toreduce the leakage of the storage capacitor between the pixel electrode150 and the scan line 120, the repairing technology of the presentinvention is applied. In this embodiment, the pulse beams are appliedonto the pixel electrode 150 to remove at least a portion of the pixelelectrode 150, which is located above the particles or the defects 186,so that an opening 188 is formed above the particles or the defects 186.Therefore, the leakage of the storage capacitor resulting from theparticles or the defects 186 between the pixel electrode 150 and thescan line 120 can be effectively reduced.

Moreover, the repairing method of the present invention can be appliedto the TFT array having the Cst over common lines (Cst on common). FIG.5A schematically shows a top view of a thin film transistor arrayaccording to still another embodiment of the present invention; and FIG.5B is a cross-sectional view along line B-B′ of FIG. 5A. Referring toFIG. 5A and FIG. 5B, the same reference number shown in FIG. 1, FIG. 5Aand FIG. 5B represent the same element, and the detail description ofwhich is omitted. In an embodiment of the present invention, a portionof the pixel electrode 150 is above the common line 122. A di-electriclayer 181, which comprises a gate-insulating layer 182 and a passivationlayer 184 extending from the thin film transistor 140, is disposedbetween the pixel electrode 150 and the common line 122. A storagecapacitor is formed between the pixel electrode 150 and the common line122. Furthermore, the particles or the defects 186 resulting fromcontamination remains in the dielectric layer 181, and the particles orthe defects 186 located between the pixel electrode 150 and the commonline 122 may result in the leakage of the storage capacitor.

FIG. 6A and FIG. 6B are thin film transistor arrays shown FIG. 5A andFIG. 5B after repairing. Referring to FIG. 6A and FIG. 6B, in order toreduce the leakage of the storage capacitor formed between the pixelelectrode 150 and the common line 122, the repairing technology of thepresent invention is applied. In this embodiment, the pulse beams areapplied onto the pixel electrode 150 to remove at least a portion of thepixel electrode 150, which is located above the particles or the defects186, so that an opening 188 is formed above the particles or the defects186. Therefore, the leakage of the storage capacitor resulting from theparticles or the defects 186 between the pixel electrode 150 and thecommon line 122 can be effectively reduced.

The TFT array and the repairing method thereof are capable of reducingabnormal electrical connection between pixel electrodes and the leakageof the storage capacitor resulting from particles or defects therein. Inaddition, the repairing method of the present invention comprises a stepof applying pulse beams to remove thin film formed over the TFT array,wherein the energy of the pulse beams can be controlled and fine-tunedprecisely, and therefore, yield of the manufacturing processes can beimproved. It should be noted that the embodiments illustrated above areused to describe the present invention, and one skilled artisan wouldunderstand that the repairing method of the present invention could beapplied to manufacture a patterned thin film. With appropriatemodification, the repairing method of the present invention can be usedremove a thin film formed over a TFT array so that the thin filmanywhere can be removed.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

1. A thin film transistor array, comprising: a substrate; a plurality ofscan lines, disposed over the substrate; a plurality of data lines,disposed over the substrate, wherein the substrate is defined into aplurality of pixel areas by the scan lines and the data lines; aplurality of thin film transistors, connected with the scan lines andthe data lines, wherein each thin film transistor is disposed in one ofthe pixel areas correspondingly; and a plurality of pixel electrodes,wherein each pixel electrode is disposed in one of the pixel areas andis electrically connected to one of the thin film transistorscorrespondingly, a storage capacitor is formed between a portion of eachpixel electrode located above one of the scan lines and the scan lines,and one of the scan lines and a defect pixel electrode of the pixelelectrodes have a particle or a defect therebetween wherein the defectpixel electrode further comprises an opening corresponding to theparticle or the defect.
 2. The thin film transistor array of claim 1,further comprising a dielectric layer disposed between the pixelelectrodes and the scan lines.
 3. A thin film transistor array,comprising: a substrate; a plurality of scan lines, disposed over thesubstrate; a plurality of data lines, disposed over the substrate,wherein the substrate is defined into a plurality of pixel areas by thescan lines and the data lines; a plurality of thin film transistors,connected with the scan lines and the data lines, wherein each thin filmtransistor is disposed in one of the pixel areas correspondingly; aplurality of pixel electrodes, wherein each pixel electrode is disposedin one of the pixel areas and is electrically connected to one of thethin film transistors correspondingly; and a plurality of common lines,disposed over the substrate, wherein a storage capacitor is formedbetween a portion of each pixel electrode located above one of thecommon lines and the common lines, and one of the common lines and adefect pixel electrode of the pixel electrode have a particle or adefect therebetween, wherein the defect pixel electrode furthercomprises an opening corresponding to the particle or the defect.
 4. Thethin film transistor array of claim 3, further comprising a dielectriclayer disposed between the pixel electrodes and the common lines.
 5. Amethod of repairing a thin film transistor array having a plurality ofpixel electrodes, wherein the pixel electrodes are electricallyconnected to each other through a residue therebetween, comprising:applying at least one pulse beam having a pulse duration between 1/20 ofa second and ¼ of a second onto the residue to remove at least a portionof the residue such that the pixel electrodes adjacent from the residueare electrically isolated.
 6. The method of claim 5, wherein the pulseduration is between 1/11 of a second and ¼ of a second.
 7. The method ofclaim 5, wherein the pulse duration is 0.1 second.
 8. The method ofclaim 5, wherein the pulse beam comprises a pulse laser beam.
 9. Themethod of claim 5, wherein a wavelength of the pulse beam is between 300nm and 500 nm.
 10. A method for repairing a thin film transistor arrayhaving a plurality of storage capacitors over scan lines (Cst on gate)or over common lines (Cst on common), wherein a pixel electrode and oneof the scan lines or one of the common lines corresponding to the pixelelectrode have a particle or a defect therebetween, the methodcomprising: applying at least one pulse beam having a pulse durationbetween 1/20 of a second and ¼ of a second onto the pixel electrode toremove at least a portion of the pixel electrode above the particle orthe defect.
 11. The method of claim 10, wherein the pulse duration isbetween 1/11 of a second and ¼ of a second.
 12. The method of claim 10,wherein the pulse duration is 0.1 second.
 13. The method of claim 10,wherein the pulse beam comprises a pulse laser beam.
 14. The method ofclaim 10, wherein a wavelength of the pulse beam is between 300 nm and500 nm.
 15. A film removing method suitable for removing a film formedover a thin film transistor array, comprising: applying at least onepulse beam having a pulse duration between 1/20 of a second and ¼ of asecond onto the film to remove at least a portion of the film.
 16. Themethod of claim 15, wherein the pulse duration is between 1/11 of asecond and ¼ of a second.
 17. The method of claim 15, wherein the pulseduration is 0.1 second.
 18. The method of claim 15, wherein the pulsebeam comprises a pulse laser beam.
 19. The method of claim 15, wherein awavelength of the pulse beam is between 300 nm and 500 nm.